286 Journal of Agricultural Research voi. x, No. 6 



been called to the fact that in some extracts like those from flour it 

 is necessary to use thymolthalein. With the extracts from silage there 

 was no difficulty in using phenolphthalein. In the same paper was 

 also discussed the necessity of titrating to a rose-red instead of only 

 to a pink. 



The results are given in cubic centimeters of a NI20 sodium hydroxid, 

 neutralized by the extract representing a 5-gm. charge of silage, and also 

 in percentage of amino nitrogen. This amino nitrogen was calculated 

 on the assumption that i c. c. of a NI20 sodium-hydroxid solution is 

 equivalent to 0.7 mgm. of nitrogen. It is assumed that for every amino 

 group fixed by the formaldehyde there is a corresponding carboxyl 

 group set free. The correctness of this assumption depends, of course, on 

 the nature of the nitrogenous compounds which take part in the reaction. 

 As all these data are comparative, the assumptions made are sufficiently 

 accurate for the present purpose. 



Percentage; of nitrogen in amino form in good silage. — For the 

 sake of brevity this form of nitrogen will be called titrable nitrogen. 

 The percentage of titrable nitrogen in silage made from fresh alfalfa 

 averages nearly 0.2, and there is only a small amount of variation in the 

 silage from the different bottles. The addition of supplements to fresh 

 alfalfa has very little influence on the amount of titrable nitrogen pro- 

 duced, though the addition of a supplement has a tendency to increase 

 the amount. The amount of titrable nitrogen in silage made from wilted 

 alfalfa averages from one-third tq twice that found in silage made from 

 fresh alfalfa. The average percentage of titrable nitrogen with the various 

 supplements to fresh alfalfa was as follows: Sound corn, 0.212; ger- 

 minated cprn, 0.214; molasses, 0.214; rye, 0.254. The average percentage 

 of titrable nitrogen with the various supplements to wilted alfalfa was 

 as follows: Sound com, 0.337; germinated corn, 0.409; molasses, 0.354; 

 rye, 0.358. In silage made from wilted alfalfa plus water the percentage 

 of titrable nitrogen is notably lower than when water was not used. The 

 percentages in wilted alfalfa plus water with the various supplements 

 were as follows: Sound corn, 0.338; germinated corn, 0.348; molasses, 

 0.314; rye, 0.334. There is a remarkable uniformity in the amount of 

 titrable nitrogen obtained from the different bottles. The addition of 

 the supplements does not have nearly as much influence as wilting. The 

 addition of water has a tendency to decrease the amount of titrable 

 nitrogen formed. 



Percentage of nitrogen in amino form in bad silage. — Under 

 the same conditions of silage-making the percentage of titrable nitrogen in 

 bad silage is only slightly greater than in good silage. However, the com- 

 parison must be limited to the alfalfa used in the same condition. The 

 amount of titrable nitrogen in bad silage made from fresh alfalfa is not 

 as large as the amount in good silage made from wilted alfalfa. The 



